opencv - opencv中cvtColor函数失败

Question

我刚刚学习图像处理，但 cvtColor 函数无法正常工作。它显示以下错误。

OpenCV Error: Assertion failed (scn == 3 || scn == 4) in cvtColor, file /build/opencv-SviWsf/opencv-2.4.9.1+dfsg/modules/imgproc/src/color.cpp, line 3737
Traceback (most recent call last):
  File "harriscorner.py", line 6, in <module>
    gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
cv2.error: /build/opencv-SviWsf/opencv-2.4.9.1+dfsg/modules/imgproc/src/color.cpp:3737: error: (-215) scn == 3 || scn == 4 in function cvtColor

实际上我正在尝试哈里斯角点检测方法，但 cvtColor fucion 不起作用。任何人的帮助将不胜感激。 这是我的代码。

import cv2
import numpy as np

filename = 'chessboard.jpg'
img = cv2.imread(filename)
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

gray = np.float32(gray)
dst = cv2.cornerHarris(gray,2,3,0.04)

#result is dilated for marking the corners, not important
dst = cv2.dilate(dst,None)

# Threshold for an optimal value, it may vary depending on the image.
img[dst>0.01*dst.max()]=[0,0,255]

cv2.imshow('dst',img)
if cv2.waitKey(0) & 0xff == 27:
    cv2.destroyAllWindows() 

Answer 1

由于您的代码在读取文件后在第一个 cvtColor 处显示错误，因此 imread 操作可能不成功。

首先确保正确读取您的图像:

filename = 'chessboard.jpg'
img = cv2.imread(filename)
cv2.imshow("src",img)
cv2.waitKey(0)#proceed to remaining code when you press a key
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

如果您无法在此 imshow 中看到图像，请检查文件路径是否正确。